1. Field of the Invention
The invention relates to a method of simultaneously splicing by fusion welding several pairs of optical wave guides by means of an arc generated between two wide welding electrodes overlapping adjacent pairs of optical wave guides.
2. Description of the Prior Art
For efficiently splicing optical wave guides it is required to carry out the splicing operation simultaneously for several pairs of optical wave guides. This especially holds if, for example, 10 optical wave guides are already assembled into a flat cable.
When splicing several pairs of optical wave guides by fusion welding in an arc struck between stationary electrodes, the problem arises to arrange all abutment points on an isotherm of the arc see (EP-B-0069832). Moreover, the electrode gap must be considerably greater than would in fact be optimal for splicing especially monomode optical wave guides.
Alternatively, the arc may be directed perpendicularly to the plane of the pairs of optical wave guides, the successive pairs being successively spliced by displacement of the welding electrodes. According to EP-A-0196137, two pairs of optical wave guides can be spliced simultaneously. This known method requires complicated mechanical device, and the overall splicing time is comparatively long.
The arrangement of several pairs of electrodes see (DE-A-29 32 723) is practically not usable with a distance between the optical wave guides in the flat cable of, for example, only 250 .mu.m because the heat dissipation through the necessarily extremely thin electrodes is not sufficient and the electrodes are burnt immediately. An electrical connection of the electrodes in parallel moreover would lead to the striking of the arc between only two electrodes.
A method of the kind described in the opening paragraph is known from Japanese Patent Application Kokai 53-73148. In this application, two pair of optical wave guides are simultaneously spliced by fusion welding between two edge-shaped welding electrodes extending over both splicing areas. However, a uniform distribution of the welding reliable manner.